Apparatus for control of highway crossing gate



March 2, 1943. c. L.- GOODLIN APPARATUS FOR CONTROL OF HIGHWAY CROSSINGGATE FiledJune 28, 1941 2H? fi ic am: 55* 10 0 A 5 G@ lfimh ZmZ W Q J JTa. n A ME- |-I|IIT I l. I S W 3% WW 2 M m Ti m B. 6 m w H. Aw w u u mwymm Fla INVENTOR HIS ATTORNEY Patented Mar. 2, 1943 UNlTED STATESAPPARATUS FOR CONTROL OF HIGHWAY CROSSING GATE Carl L. Goodlin, PennTownship,

Allegheny County, Pa., assignor to The Union Switch & Signal Company,Swissvale, Pa., a corporation of Pennsylvania Application June 28, 1941,Serial No. 400,262

2 Claims. (Cl. 246-430) My invention relates to apparatus for control ofhighway crossing gates, and more particularly to apparatus for controlof highway crossing gates that are automatically governed by trains.

An automatic highway crossing gate is ordinarily controlled by a trackcircuit of a track section in the approach to the intersection of thehighway and railway. The gate arm is normally held at a vertical ornon-obstructing position as long as the approach track section isunoccupied and is lowered to a horizontal or obstructing position acrossthe highway in response to a train occupying the approach section, theapproach section being of sufiicient length to assure that the armreaches its lowered position not less than some predetermined period oftime prior to the head end of the train entering the intersection.

To avoid lowerin the gate arm immediately in front of or on top ofautomobiles or other highway vehicles, a preliminary warning in the formof bells or lights or both is provided for a short period before thegate arm leaves its vertical position. When the train has passed overthe intersection and is receding therefrom, the motor of the gatemechanism is energized to raise the gate arm to its vertical position,the operation of raising the gate arm requiring several seconds. It mayhappen that a second train is following the first train close enough toenter the approach section while the gate arm is being raised subsequentto a first train passing over the intersection and thereby cause thegate arm to be returned to its lowered position from some intermediateposition with the result that highway trafiic starting to go over thetrack after having waited for the first train to pass is given nowarning that the gate is to be lowered and it descends directly in frontof or on top of the highway vehicle.

In view of such circumstances, a feature of my invention is theprovision of apparatus for the control of highway crossing gatesincorporating novel means wherewith the movement of a gate arm to itsnon-obstructing position, once started, is completed withoutinterruption.

Another feature of my invention is the provision 7 of apparatus for thecontrol of automatic highway crossing means wherewith the gate arm whenbeing moved to its raised position and a second train enters theapproach section, the control causes the gate arm to continue itsmovement to the the gate mechanism for raising the gate arm, onceinitiated by the main control circuit, the stick circuit control becomesefiective to continue such operation until the arm is raised to its fullvertical position when the stick circuit is opened and the main controlcircuit is again made effective: for holding the arm at its verticalposition.

I shall describe one form of apparatus embodying my invention, and shallthen point out the novel features thereof in claims. 1

' The accompanying drawing is a diagrammatic view showing one form ofapparatus embodying my invention when used with an automatic highwaycrossing gate.

' It will be understood that my invention is not limited to apparatusfor automatic control of a highway crossing gate and is useful withapparatus where the gate is entirely manually controlled or where thegate is controlled in part manually and in part by trains. This one formof apparatus will serve to illustrate the several different places whereapparatus embodying the invention is useful. Q}

Referring to the drawing, the reference characters la and lb designatethe track rails of a railway intersected at grade by a highway H and atwhich intersection two highway crossing'gates GI and G2 are located. Thetrack rails la' and lb are formed by the usual insulated rail jointswith two track sections, one on each side of the highway, a section D-Ebeing formed on the left of the highway H as viewed in the drawing, anda section EF being formed to the right of the highway. In other words,section D-Fl is an approach section with respect to the highway intersection when east-bound trains are considered, and section E-F is anapproach section with respect to the highway intersection when westboundtrains are considered.

Each track section D-E and EF is provided with a track circuit, whichincludes a current source such as a battery It connected across therails at one end of the section and a winding of an interlocking relayIR connected across the rails at the other end of the section, winding!I of relay IR being included in the track circuit of section D-E andwinding i2 of relay IR being included in the track circuit of sectionE-F. The connections of windings H and I! to the track rails are thoseof common practice to provide the so-called extended shunt protection aswill be readily understood by an inspection of the drawing, and theseconnections need not be described in detail since they form no part ofmy invention.

The highway crossing gates GI and G2 are shown conventionally and arelocated one ,on. each side of the railway track and are adaptable ofbeing operated in a manner such that their respective gate arms l3 andI4 are moved between a lowered position where the arm extendshorizontally across at least a portion of crossing gate GI and G2 issimilar to that shown and described in Letters Patent of the UnitedStates No. 1,138,087, granted to John P. Coleman on May 4, 1915, forRailway signals, and to which patent reference is made for a fullunderstanding of the construction of such mechanism. In the applicationthe gate arm is an extended form of the semaphore of the patent.

The mechanism and the control thereof for gate GI only is shown in thedrawing for the sake of simplicity, since the two gates are alike andthe mechanism of gate G2 and its control would be but a duplication ofthose for gate GI.

Looking at the gate GI mechanism, a motor MI, a slot magnet SM and acircuit controller CI are among the essential elements of the mechanism.Motor MI comprises an armature I5 and a field winding I6 and isoperatively connected by suitable drive mechanism (not shown) to thegate arm I3. Gate arm I3 is biased by gravity to its lowered orobstructing position,

and the motor MI when energized and eifective- 1y coupled to the drivemechanism, is operative to raise the arm I3 against thebiasing force toits raised or non-obstructingposition, the full movement of the armbeing approximately 90 degrees. In the following description, thelowered or obstructing position of the gate arm will be considered asthe 0 degree position, and the raised position of the arm will beconsidered as the 90 degree position.

Slot magnet SM includes a high resistance or holding winding I1 and alow resistance or pick-up winding I8. The slot magnet SM governs theoperation of motor MI for driving the gate arm, the arrangement beingsuch that when both windings I1 and I8 are energized, the motor circuitis closed whereby the motor is operated to raise the arm, winding I8serving as an aid to winding I1 in closing the motor circuit. When theraised position of the arm 7 is effected, winding I8 is deenergizedalong with the motor and the arm is held at the raised position byenergization of winding I1 only. The slot magnet armature has mountedthereon contacts by which the motor operating circuit and other circuitslater to be described are controlled.

. Circuit controller CI is operatively connected to the mechanism foropening and closing circuit controlling contacts of which only the twocontacts 2 and 8 are shown in the drawing. Contacts 2 and 8 are shownconventionally and each is closed except at the full raised or 90 degreeposition of the gate arm. That is to say, each contact 2 and 8 is closedbetween the 0 and 89 degree movement of the gate arm as indicated on thedrawing.

The control means includes a control relay XR and the interlocking relayIR. Relay XR is slow releasing in character and is normally ener gizedover a circuit including terminal B of any convenient source of currentsuch as a battery not shown, front flagman contacts I9 and 20 ofwindings II and I2, respectively, of relay IR,

winding of relay XR and terminal C- of the samesource of current. Thatis to say,'relay XR is energized and picked up when the track sectionsD-E and EF are unoccupied and also when ,either section is occupied by atrain receding from the highway and the other section is unoccupied.Relay XR in turn governs control circuits for the windings I1 and I8 ofslot magnet SM. The control circuit for winding I1 includes terminal B,front contact 2I of relay XR, Wire 22, winding I1, wire 42 and terminalC. The control circuit for winding I8 can be traced from terminal B overfront contact 2I of relay XR, Wires 22 and 23, contact 2 of circuitcontroller CI when closed, wire 24, winding I8 and wire 42 to terminalC.

As here shown, a motor operating circuit extends from terminal B overcontact 8 of circuit controller CI and closed at the 0 to 89 degreeposition of the gate arm, wire 25, front contacts 26 and 21 in multipleof winding I1, wire 28, motor armature I5, motor field winding I8, andwire 42 to terminal C. It is to be noted that motor M I is provided witha low resistance circuit which causes the motor to act as a generatorand cushion the movement of the gate arm I3 when moved to its loweredposition by the biasing element. Such low resistance circuit can betraced from the right-hand terminal of motor armature I5 over wire 28,back contacts 29 and 30 in multiple of winding I1, wire 3I, a resistor32, motor field winding I8 and to the left-hand terminal of motorarmature I5.

According to my invention, I provide winding I1 with a special stickcircuit and winding I8 with a special control circuit. The stick circuitfor winding I1 includes terminal B, contact 8 of controller CI, wire 25,front contact 33 of winding I1, winding I1 and wire 42 to terminal C.The special control circuit for winding I8 is the same as the stickcircuit for winding I1 up to and including front contact 33 and henceover wire 23, contact 2 of controller CI, wire 24, winding I8 and wire42 to terminal C.

In accordance with standard practice, the interlocking relay IR alsocontrols a warning signal circuit by which warning bells 0r warninglamps, or both, are operated, such circuit being closed over a full downcontact 34 of winding II of relay IR or a full down contact 35 ofwinding I2. The remaining portion of such warning circuit is not shownsince it forms no part of my invention, and that portion shown on thedrawing is suflicient for a full understanding of the invention.

Normally, that is, when both section D-E' and E-F are unoccupied, theinterlocking relay IR is picked up causing control relay XR to be inturn picked up and the warning circuit to be opened. Control relay XRwhen picked up closes the circuit for winding I1 and that winding isenergized to hold the gate GI at its raised position, it being assumedthat the gate arm has been raised in a manner to shortly appear.Assuming an eastbound train approaches the intersection to enter tracksection D-E, winding II of interlocking relay IR is deenergized to openits front contact I9 and to close its back contact 34. The closing ofback contact 34 completes the warning signal circuit causing the bellsand lamps controlled by that circuit to be immediately operated as aWarning'indication to highway users that a train is approaching and thatthe gate GI is about to be lowered. The opening of front contact I9 ofWinding, II deenergizes control relay XR and that relay is released atthe end of its slow release period to open the circuit for winding II ofthe slot magnet, with the result that the gate mechanism is released andgate arm 13 is moved to its lowered position by the biasing element ofthe mechanism. As stated hereinbefore, the approach section DE is madeof suflicient length to assure that the gate arm I3 is moved to itslowered position before the head end of the train enters theintersection. When the head end of this eastbound train clear theintersection to enter the section E-F, the winding I2 of relay IR isshunted and its contacts released to the interlocked position of therelay. When the rear of the train vacates the section DE, winding 1 I ofrelay IR is reenergized and picked up to close the circuit for controlrelay XR and in turn close the circuit for windings l1 and I8, theenergizing of both winding l1 and I8 being effective to close the motorcircuit and cause operation of the motor for driving the gate arm 13.That is, with both windings l1 and I8 energized to close front contacts26 and 21, the motor operating circuit is closed and the motor isoperated to move the gate arm. At the 90 degree position, contacts 2 and8 of controller Cl are opened to open the motor operating circuit andalso the circuit for winding [8. It is to be noted that when windings l1and I8 become energized to close front contact 33, the stick circuit forwinding l1 and the special control circuit for winding I 8 are closedand consequently if a second eastbound train should now enter theapproach section D-E shunting winding Ii of relay IR and bringing aboutthe release of control relay XR to open the main control circuit forwindings l1 and I8, winding I! is retained energized over its stickcircuit and winding [8 is retained energized over its special controlcircuit governed by winding l1 and the operation of raising the gate armI3 is continued. When the 90 degree position of the gate arm is reached,however, contacts 2 and 8 of controller Cl are opened with the resultthat the stick circuit for winding [1 and the special control circuitfor winding 18 are opened. It follows, therefore, that when the 90degree or full vertical position of the gate arm is reached, it isimmediately lowered to its lowered position by the biasing element ofthe mechanism in the event the control relay XR is released due to asecond eastbound train in the approach section D-E. However, the gatearm i3 is not returned from any intermediate position to its loweredposition due to the second eastbound train entering the approachsection, and hence it is not lowered immediately in front of or on topof any highway vehicle that may have started to pass Over theintersection subsequent to the first train clearing the intersection.When winding II of relay IR is released in response to the secondeastbound train entering the approach section DE, the warning signalcircuit is reclosed and these devices operated as a warning indicationto the highway users that a train is approaching the intersection andthat the gates are about to be lowered.

Operation of the apparatus in response to a westbound train issubstantially the same as that described in connection with an eastboundtrain and a description of the operation of the apparatus for awestbound train is readily apparent from an inspection of the drawingtaken in connection with the description of the operation of theapparatus for an eastbound train.

Although the main control relay XR for gate GI is here shown as governedby track circuits, it is apparent that relay XR and in turn gate GI maybe governed by a manually operable switch if desired.

Although I have herein shown and described but one form of apparatus forcontrol of highway crossing gates embodying my invention, it isunderstood that various changes and modifications may be made thereinwithin the scope of the appended claims without departing from thespirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a highway crossing gate located at an intersection ofa highway and a railway and biased to an obstructing position andoperable to a non-obstructing position; a gate mechanism including amotor, a slot magnet and a circuit controller; said motor operable tomove the gate to its non-obstructing position, said slot magnet operableto hold the gate at its non-obstructing position and provided with aholding and a pick-up winding and circuit controlling contacts, anormally energized control relay governed by railway trafiic anddeenergized in response to a train approaching the intersection, a firstcontrol circuit including a front contact of said relay to energize saidholding winding, a second control circuit including said front contactof the control relay and a contact of said circuit controller closedexcept at the non-obstructing position to energize said pick-up winding,an operating circuit including a contact of said controller closedexcept at the non-obstructing position and a front Contact of said slotmagnet for operating said motor, and stick circuit means including saidlast mentioned controller contact and a front contact of said slotmagnet to energize both said holding and pick-up windings to continuethe movement of said gate to its nonobstructing position once suchmovement is started and a train approaches the intersection todeenergize said control relay.

2. In combination, a highway crossing gate located at an intersection ofa highway and a railway and biased to an obstructing position andoperable to a non-obstructing position; a mechanism for said gate andincluding .a motor for operating the gate to its non-obstructingposition, a slot magnet for controlling said motor and for holding thegate at its non-obstructing position and a circuit controller; said slotmagnet comprising a holding and a pick-up winding and circuit contactswhich become closed when both of said windings are energized and areretained closed when said holding winding alone is energized, a controlrelay, a first circuit including a contact of said relay to energizeSaid holding winding, a second circuit including said relay contact anda contact of said circuit controller opened only at the non-obstructingposition of the gate to energize said pick-up winding, an operatingcircuit including a contact of said circuit controller opened only atthe non-obstructing position of the gate and a front contact of saidslot magnet for operating said motor, and a stick circuit including thelast mentioned controller contact and a front contact of said slotmagnet to energize said holding winding to continue operation of thegate to its non-obstructing position independent of said control relay.

CARL L. GOODLIN.

